1. Field of the Invention
The present invention relates to a method and an apparatus for the protection of a data transmission network consisting of a signal bus provided with terminal impedances and of signal devices connected to the bus.
A data transmission network implemented using pulse transformers and balanced with terminal resistors is liable to connection errors. A faulty connection may inhibit the whole bus. Moreover, since the devices using the bus are connected to it in parallel, an incorrect voltage supplied into the bus at any point may destroy all the devices connected to it. This involves maintenance problems and increases the costs. Further difficulties are encountered if the state of the bus is not known before a data transfer operation attempt.